A continuous vacuum deposition coating apparatus for coating the surface of a metal strip with another metal, a steel strip with zinc for instance is known. This apparatus comprises an evacuable vacuum deposition chamber in which an evaporation chamber is place and the entrance and the outlet of said vacuum deposition chamber is closed by a seal roll means which allow entering and egressing of the metal strip while maintaining vacuum condition of the chamber. Such apparatus is typically disclosed in Japanese Patent Publication No. 18646/72, No. 20950178, etc., for instance.
In known vacuum deposition apparatuses, the evaporation chamber is provided with a vapor channel of constant dimension. Therefore, there was a defect that when a metal strip the width of which is narrower than the width of the channel is coated, the strip is not coated to a uniform thickness over the whole width thereof. We have devised a new continuous vacuum deposition apparatus which can provide a coating with transversally uniform thickness.